Elongated cables are found in use in many industries including those that conduct deep drilling, such as within the oil drilling industry. These cables may be used to transmit information and data from a drilling region having the drilling equipment to a control center located remote to the drilling region. Many oil drilling regions are located deep within the Earth's crust, such as those seen with onshore and offshore drilling. The drilling region may be 5,000 feet or more from a control center located on the Earth's surface or a control center located on water at sea level. A cable of 5,000 feet or more may have a high weight that, when located vertically down a drilling hole distorts the structure of the cable itself. This may result in a failure of the cable or a deformity of the cable that renders it more inefficient than a non-deformed cable.
It is common for cables used in industries today to be subjected to high-temperature applications, as well as potential damaging situations. For example, cables may be subject to high temperatures from oil drilling operations, equipment, or other devices that may create heat. A metal casing is often used around the cable to help prevent transfer of the heat into the inner components of the cable. This metal casing, for example, may seal off any gassing of the inner materials of the cable, as well as prevent rocks, sharp objects, or other potentially damaging items from causing harm to the cable. When subjected to heat, many materials will deform or give off volatiles that will lower the insulation resistance of the insulating materials, especially when temperatures exceed 250° C. Materials such as perfluoroalkoxy (PFA) may be used up to temperatures of approximately 250° C., but may be unsuccessful in higher temperature.
Sensor cables may be used with polymers in, under, and over a metal tube. The polymer inside the tube is an electrical insulator, but also must hold to the tube with sufficient force to transfer forces from the conductor to the tube so the conductor does not break under its own weight. When thermoplastic polymers are used under tube and a jacket is placed over the tube it was found that the pullout strength of the core decreased. This was not initially noted under non-operational conditions, but when the cable, with or without a jacket, was subjected to high temperatures or other operational conditions, the decreased pullout strength of the core was apparent.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.